1. Meiofauna (invertebrates that pass through a 1-mm mesh sieve, but are retained on a 40-µm mesh) represent the most abundant and diverse animal group on Earth, but empirical evidence of their role in benthic respiration, production and carbon cycling across ecosystems is not well documented. Moreover, how meiofauna respond to changing oxygen conditions is poorly understood.
2. We further developed an incubation system, in which oxygen and temperature conditions are easily controlled and single meiofaunal nematode respiration is resolved in glass capillary tubes, using Clark-type oxygen microsensor. We performed the respiration measurements after exposing nematodes to different ambient oxygen concentrations, which resulted in 3–60 µM O₂ during hypoxic and 80–210 µM O₂ during oxic incubations in close proximity to the respective nematodes.
3. Individual nematode respiration rates ranged from 0.02 to 1.30 nmol O₂ ind.⁻¹ day⁻¹ and were 27% lower during hypoxic than oxic incubations. Rates derived from established allometric relations were on average fourfold higher than our direct measurements.
4. The presented method is suitable for single nematode respiration measurements and can be adapted to a wide range of experimental conditions. Therefore, it can be used to assess meiofauna contribution to ecosystem processes and investigate species-specific responses to changing environmental conditions, for example, oxygen stress, increasing water temperature.

中文翻译：

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一种基于微传感器的测量单个线虫呼吸的方法

1. 小型动物群（通过 1 毫米筛网的无脊椎动物，但保留在 40 微米的筛网上）代表地球上最丰富和多样化的动物群，但它们在整个生态系统的底栖呼吸、生产和碳循环中的作用的经验证据没有很好的记录。此外，人们对小型动物如何应对不断变化的氧气条件知之甚少。
2. 我们进一步开发了一种孵化系统，其中氧气和温度条件易于控制，并且使用克拉克型氧气微传感器在玻璃毛细管中解析单个小型动物线虫呼吸。我们将线虫暴露于不同的环境氧浓度后进行呼吸测量，这导致在缺氧期间产生 3–60 µM O ₂，在靠近相应线虫的有氧孵化期间产生80–210 µM O ₂。
3. 个体线虫呼吸速率范围为 0.02 至 1.30 nmol O ₂ ind。^-1 天^-1并且在低氧孵育期间比有氧孵育低 27%。从建立的异速生长关系得出的比率平均比我们的直接测量高四倍。
4. 所提出的方法适用于单线虫呼吸测量, 可以适应广泛的实验条件。因此，它可用于评估小型动物对生态系统过程的贡献，并研究物种对环境条件变化的特定反应，例如氧气压力、水温升高。